We have tried
to be accurate with the above table but cannot be held responsible for
inaccuracies.
Go back to first principals and double check your calculations if the
result is 'mission critical'.

The scientific notation
used in the factors column helps to reduce long numbers
to a manageable width. E+01 means moving the decimal point
one space to the right so 1.00E+01 is shorthand for 10,
then 1.33E+00 stays at 1.33 and 1.33E-01 becomes 0.133.
The format tends to be used when the figure gets longer
so E+09 or E-09 cuts out a lot of noughts.

Impossible Conversions
Remember that you cannot create energy only convert it.
Likewise, you will not find a conversion from pounds to
metres - the basic units
must remain the same - mass converted to mass, length
converted to length, et al.

You won't usually find a conversion from kilograms to
grams - the prefix 'kilo' means '1,000' so a kilogram
is in fact 1,000 grams in the same way as a kilometer
is 1,000 metres [or about 1,000 yards in 'old money'].
I have put a few in the table because visitors have asked
for them. More examples can be found on the
prefix table.

One handy metric link between units to remember is that 1 Litre [1000cc]
of pure water weighs 1 kilogram.

If accuracy is critical beware of old versions of MS Excel which had problems
rounding off numbers.

Metrication is a great help but has also created anomalies; I have seen
pressure gauges changed from a commonly used psi to kg/cm.sq., bar, pascal,
kPa and atmos but will no doubt move to a popular metric standard in a
few decades.